The present invention relates generally to the raising and lowering of convertible furniture and more particularly to convertible furniture with: an improved torsion bar system that mechanically aids in the raising of furniture components, a self-standing support means that stabilizes the furniture without attaching to a separate structure, a self-energizing latching means that automatically latches the furniture in a lowered position, and a retaining means for retaining articles left on the furniture components during retraction.
The present invention is well suited for convertible furniture that is heavy and exerts large loads as it retracts into position such as that disclosed in U.S. Pat. Nos. 4,070,715, 4,318,195 and 4,476,592. The individual features of this invention aid a user in overcoming the problems associated with these large loads. One such feature is an improved torsion system that utilizes two cantilevered bars and an adjustable clamping means. This configuration permits more potential energy to be stored at a reduced torsional stress. Torsion systems have been previously utilized with convertible furniture, but those configurations utilized single bars that individually extended from one end of the base assembly to the other. A typical example of this configuration is demonstrated in U.S. Pat. No. 4,597,568 (Drexhage).
In general, torsion systems are used with convertible furniture to store potential energy as the furniture components are lowered. The amount of potential energy stored in a torsion bar is a function of torsional stress. Torsional stress is defined by the amount of twist per unit length of the bar. Since the length of previously used torsion bars has been limited to the width of the base assembly, a need has been recognized for a torsion bar system that increases torsion bar length without increasing the size of the base assembly. This would allow potential energy to be stored with a decreased amount of twist per unit length. Accordingly, the present invention provides a cantilevered torsion bar system that can potentially double the effective length of a conventional torsion bar within a conventional base assembly.
When convertible furniture utilizes a torsion bar system, energy stored in each bar places tremendous moments on the stationary base assembly. With previously known convertible furniture, it has been necessary to fixedly attach the base assembly to a support structure; typically, the support structure used is a floor or a wall. By fixedly attaching the base assembly to a rigid structure, the energy stored in each bar is held in check. Thus, the torsion bars are not permitted to recoil and flip the base assembly from its footing. Unfortunately, once this type of convertible furniture is installed, it is very difficult to move, and if it is moved, mounting holes in the structure and its covering remain. Alternatively, a very large base assembly has been utilized to support and stabilize convertible furniture without having to be attached to a wall or floor. However, this type of base assembly required a large structure which enclosed much of the furniture components.
Thus, a need has been recognized for a self-standing support means that requires minimal base assembly structure to stabilize convertible furniture. Accordingly the present invention incorporates at least one generally horizontal out rigger. This eliminates the need to fasten the base assembly to a floor or wall structure.
Another feature of this invention is its utilization of a self-energizing latching means to automatically latch the furniture in place when fully lowered. This latching means permits the user to simply lower the convertible furniture into position without manually actuating a latch.
Yet another feature of this invention is the incorporation of a retaining means for retaining articles left on the furniture components. This retaining means prevents articles left on the furniture components from sliding off the component and into the base assembly during retraction. As a result, articles inadvertently left on the components are not lost within the base assembly, and articles purposely placed on the components are held in place.